arm64: efi: Account for the EFI runtime stack in stack unwinder

[ Upstream commit 7ea55715c421d22c1b63f7129cae6a654091b695 ]

The EFI runtime services run from a dedicated stack now, and so the
stack unwinder needs to be informed about this.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
index 5a0edb0..327cdcf 100644 (file)
--- a/arch/arm64/include/asm/stacktrace.h
+++ b/arch/arm64/include/asm/stacktrace.h
@@ -104,4 +104,19 @@ static inline struct stack_info stackinfo_get_sdei_critical(void)
 #define stackinfo_get_sdei_critical()  stackinfo_get_unknown()
 #endif
 
+#ifdef CONFIG_EFI
+extern u64 *efi_rt_stack_top;
+
+static inline struct stack_info stackinfo_get_efi(void)
+{
+       unsigned long high = (u64)efi_rt_stack_top;
+       unsigned long low = high - THREAD_SIZE;
+
+       return (struct stack_info) {
+               .low = low,
+               .high = high,
+       };
+}
+#endif
+
 #endif /* __ASM_STACKTRACE_H */

diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index 117e2c1..8315430 100644 (file)
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -5,6 +5,7 @@
  * Copyright (C) 2012 ARM Ltd.
  */
 #include <linux/kernel.h>
+#include <linux/efi.h>
 #include <linux/export.h>
 #include <linux/ftrace.h>
 #include <linux/sched.h>
@@ -12,6 +13,7 @@
 #include <linux/sched/task_stack.h>
 #include <linux/stacktrace.h>
 
+#include <asm/efi.h>
 #include <asm/irq.h>
 #include <asm/stack_pointer.h>
 #include <asm/stacktrace.h>
@@ -186,6 +188,13 @@ void show_stack(struct task_struct *tsk, unsigned long *sp, const char *loglvl)
                        : stackinfo_get_unknown();              \
        })
 
+#define STACKINFO_EFI                                          \
+       ({                                                      \
+               ((task == current) && current_in_efi())         \
+                       ? stackinfo_get_efi()                   \
+                       : stackinfo_get_unknown();              \
+       })
+
 noinline noinstr void arch_stack_walk(stack_trace_consume_fn consume_entry,
                              void *cookie, struct task_struct *task,
                              struct pt_regs *regs)
@@ -200,6 +209,9 @@ noinline noinstr void arch_stack_walk(stack_trace_consume_fn consume_entry,
                STACKINFO_SDEI(normal),
                STACKINFO_SDEI(critical),
 #endif
+#ifdef CONFIG_EFI
+               STACKINFO_EFI,
+#endif
        };
        struct unwind_state state = {
                .stacks = stacks,